Piston-ring clamping device



July 3, 1928. 1,675,603

H. S. GRAVES PISTON RING CLAMPING DEVICE Filed Sept. 16, 1926 Patented July 3, 1928.

UNITED STATES PATENT OFFICE.

HARRY sJcaavss, or ns/mom, M CHIGAN.

irrs'ron-nme cnamrme navrcn.

Application in September 16,1926. Serial m. maaos.

This invention relates to .a piston ring clamping device that may be termedan assembly tool ora tool for compressing piston rings. Such a tool or device is used for bolding a multiplicity ofpiston rings, side by side, so that'the peripheries or outer walls of the rings may be machined or otherwise treated.

In the production of cast piston rings there are inequalities so that it becomes necessary to turn down the rings'to a desired diameter. Irrespective of what the inequali ties may be in connection with the peripheries or outer walls of the rings, my clampin device permits of the rings being assem led about a holder, compressed or contracted about the holder to snugly engage the same,

and then held in such condition so that the holder may be (placed in a lathe or other machine employs for turning down the outer walls of the rings to thereby establish a umform exterior diameter for all the rings on the holder. In order that the compressing or contracting operation may be expeditious l and economically performed it is essential that a yieldable means be em loyed to engage the outer walls of the rings ecause the cast or embryo rin before being machined, are of difi'erent t icknesses. This is the main inequality between cast rings and it becomes necessary to employ a yieldable compressing means to compensate for such inequalities when mounting the rings for a lathe operation.

' My tool or device is particularly charpcterized by a holder for the rings and yie able compressing means for placmg the rings snugly on the holder, so that endwise pressure may be brought to bear to sidewise clamp the rings in position.

' The above and other features of my invention will hereinafter appear and reference will now be had to the drawing, wherein Figure 1 is a longitudinal sectional view oi the ring clamping device, and

Fig. 2 is a cross sectional view of the same.

In the drawing, the reference numeral 1 "denotes an arbor that may be in the form of a bolt having a large cylindrical head 2 and a small centerin head 3, or the largehead 2 ma be detacha le relative to the arbor. loc washer 4 and a nut 5 are adapted to be placed on the threaded end 6 of the arbor or bolts and this end of the arbor or bolt has the usual centering recess 7 similar to the 0' recess 8 of the head 3.

Detachablymounted on the arbor 1 is a y A- when cylindrical holder 8 on which may be assembled a multiplicity of splitiston rings 9, said rings being arranged si e'fby side and adapted to have the inner walls 10 snugly engage the smooth uniform diameter outer wall of the holder 8. The head 201': the arbor 1 is of reater diameter than'the holder 8 so as to orman annular abutment 11 at one end of the holder for one of the end piston rings. 12, corresponding in diameter to the head-2 is adapted to form an end abutment at the opposite end of the holder 8: It is therefore possible to adjust the nut 5 so as to cause the heads 2 and 12 to exert a pressure against the endmost rings to sidewise clamp these rings assembled about the holder 8.

For the purpose of causing the rings 9 to snugly fit the holder 8 a two-part cylindrical casing is employed composed of semicylindrical fans or members 13 and 14 hingedly or otherwise ivotally connected to- A detachable head or abutment g'ether, as at 15 so t at the semi-cylindrical members may be opened and closed relative to-the holder and the rings thereon. The

a casing member 14 has a pivoted eye bolt. 16

equalities that wouldrender it difiicult to individually clamp the rings about the holder. Therefore the casing members 13 and 14 are provided with yieldable ring enga ing members or cushions 18, which are pre erably in the form of barsor strips of rubber or other yieldable material mounted in longitudinal grooves or ways 19 provided therefor in the inner walls of the casing members 13 and 14. These grooves or ways are equally spaced about the inner walls of the casing members and disposed longitudinally thereof with the depth of each groove less than the thickness of a member 18 so that a portion of the member will protrude from the groove and withstand compression placed in engagement with the outer walls of the rings 9. This is best shown in '2 where a plurality of these members a 0rd ample means of bracing the rings on the holder 8. These resilient members can ield, as best shown in Fi 1 because of any inequalities in the'extern diameters of the piston rings. Obviousl .the ring en 'ng members 18, when mad of rubber, wilI be subjected to wear and for this reason the rooves 19 and the members 18 are rectanguar in cross section so that the members 18 may be repositioned from time to time to expose the side walls of each memberto wear by engaging the rings. This is a distinct advantage compared to asleeve linin for the casing members 13 and 14, and that a multi-point engagement of the rin produces better results than an inner perip eral engagement of thering.

In practice the piston rings are assembled on the holder with the heads 2 and 12 simply' holding the rings side by side without any perceptible clamping action. The holder and its rings are then placed in the cylindrical casing and the casin members clamped together to bring su cient pressure to bear on the rings to cause the same to firmly clamp the holder 8. While held in this condition pressure is brought to bearon the heads 2 and '12 to sidewise clamp the rings on the holder 8 and prevent any expansion or radial movement of the rings. With the rings so held the casing may be removed, the arbor 1 placed between the head and tail stocks of a lathe and the outer walls of the rings turned down to a desired diameter. It is by virtue of the holder 8 that the inner and outer diameter of all of the rings become uniform after the outer walls are machined, and the holder may be made of such size that the split ends of each ring may be brought into proximity to each other so that the split ends will not interfere with any turning do n operation.

One embo iment of my invention has been illustrated, but it is to be understood that the structural elements are susceptible to such variations and modifications as fall within the scope of the appended claims.

What I claim is 1. In a tool for exerting closing pressure upon piston rings, a holder for the piston rings, a casing adapted to be placed about the piston rings on the holder to exert pressure on the piston rings, invertible strips of ieldable material in said casing ada ted to ar on the piston rings of said ho der and means at the ends of said holder ada for clamping the iston rings on said ho der.

2. A tool as cal ed for in claim 1, wherein said strips of material are longitudinally dis posed in said casin and equally spaced in the inner wall of said casing.

3. A tool as called for in claim 1, wherein said casing is longitudinally grooved to receive said strips, and said stri s and grooves of a cross sectional shape whlch permits of said strips being shifted to present various ring engagin faces.

4. A tool 0 the type described comprising a holder on which may be assembled a multiplicity of split piston rings arranged side by side, a caslng adapted'to be placed about thepiston rings on the holder to exert an inward pressure on the rings, invertible resilient strips set in the inner'wallof said casing. and providing a multiplicity of spaced apart ring engaging contact points with the piston rings, and means at the ends of said holder adapted 'for clamping said rings on said holder.

5. In a piston ring clamping device wherey in rin er an are assembled side by side on a holdadapted to be clamped thereon by endwise pressure at the ends of said holder, 3

and wherein a casing or the like instrumentality is employed for exerting pressure on,

the rings before clamping the rings on said holder; resilient means carried by said casing to provide a yieldable pressure of said casing on said rin said resilient means comprising longitu mally, disposed spaced apart strips in the wall of said casing, each strip having a configuration to provide a plurality of ring engaging faces brought into active position by changing the position of said strips in said casin In testimony whereof aflix mysignature.

HARRY S. GRAVES. 

